Lightweight hydraulic jack

ABSTRACT

A lightweight hydraulic jack having a gray iron sleeve embedded within a cast aluminum housing, a steel plunger mounted for reciprocal motion within the sleeve, the sleeve being provided with an annular shoulder and a number of longitudinal ribs to prevent movement of the sleeve with respect to the housing. Hydraulic fluid is pumped from a reservoir in the housing into the sleeve and from the sleeve back to the reservoir through steel valve seats which are positioned at the control points in a fluid passage network in the housing.

nited States Patent 1191 Sessody Oct. 29, 1974 [54] LIGHTWEIGHT HYDRAULIC JACK 3,757,523 9/[973 Resuggan 254/93 H [75] Inventor: Donald W. Sessody, Milwaukee, FOREIGN PATENTS OR APPLICATIONS 126,701 /1919 Great Britain 92/171 [73] Assignee: Applied Power Inc., Milwaukee,

Wi Primary Examiner-Al Lawrence Smith 1 Assistant ExaminerRobert C. Watson [22] Wed: June 1973 Attorney, Agent, or Firm--James E. Nilles [21] Appl. No.: 366,582

[57] ABSTRACT [52] US. Cl. 254/93 H A lightweight hydraulic jack having a gray iron sleeve [51] Int. CL... 866i 3/24 embedded within a cast aluminum housing, a steel [58] Field of Search 254/93 H, 93 R; 60/477; plunger mounted for reciprocal motion within the 92/169, 171 sleeve, the sleeve being provided with an annular shoulder and a number of longitudinal ribs to prevent [56] References Cited movement of the sleeve with respect to the housing. 1 UNITED STATES PATENTS Hydraulic fluid is pumped from a reservoir in the 2,352,390 6/1944 Kirkland... 254/93 H housing the sleeve and from the i back 2 527 428 10/1950 Kemerer... 254/93 11 the reserm" through Steel Valve Seats wh'ch are 2173 27 16 2/1956 Pearne 254/93 H tioned at the Control Points in a fluid Passage network 3,047,269 7/1962 Renshaw.. 254/93 H ll! the housing. 3,439,586 4/1969 Holtan 92/169 3,743,448 7/1973 Dorn 92/171 4 Clam, 15 D'awmg I lllllllll 112\ f 10 12 i 1 12 2s 16 f i 88 15 J 62 64 22 114 7 624 38 100,

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- Pmmmmm sum 3 or s 1 LIGHTWEIGHT HYDRAULIC JACK BACKGROUND OF THE INVENTION Hydraulic jacks of the type contemplated generally operate at high pressure up to 10,000 psi. It has been the general practice to manufacture these jacks from heavy materials such as iron and steel which are capable of withstanding high hydraulic loads at these pressures. Therefore, as the rating 'of the jack increased the weight of the jack also increased.

SUMMARY OF THE INVENTION The present invention provides a lightweight hydraulic jack which is capable of handling heavy loads without any substantial increase in weight at higher rated loads. This has been accomplished by casting the housing from aluminum and embedding an iron sleeve in the casting as an integral part of the base of the jack. The sleeve is prevented from moving in the housing by a shoulder on the bottom and a number of longitudinally extending ribs along the sides to allow for machining after casting.

The life of the jack has been extended by using steel parts in all instances where there is flow of hydraulic fluid under high pressure. The strength of the bond between the sleeve-and the casting is protected by an O- ring seal located in a space provided between the sleeve and the casting. 7

Other objects and advantages will become apparent from the following description.

DRAWINGS FIG. 1 is a perspective view of the jack of this invention taken from the upper left hand side;

FIG. 2 is a perspective view of the jack of this invention taken from the upper right hand side;

FIG. 3 is a perspective view of the back of the jack;

4 is a front view in elevation of the jack; 5 is a left side view in elevation of the jack; 6 is a rear end view of the jack; 7 is a top plan view of the jack; I; is a right side view in elevation of the jack; FIG. 9 is a bottom view of the jack; FIG. 10 is a top view of the jack partly broken away to show the hydraulic flow passages in the jack housing;

FIG. FIG. FIG. FIG. FIG.

FIG. is a cross-sectional view taken on line 15-15 of FIG. 11 showing the retaining ribs of the sleeve.

DESCRIPTION OF THE INVENTION The hydraulic jack 10 of the present invention generally includes a lightweight aluminum base 12 having a steel plunger and iron sleeve assembly 14 and a fluid reservoir 16. Fluid is pumped from the reservoir 16 to the piston and cylinder assembly 14 by means of a pump assembly 18 and is returned from the piston and cylinder assembly 14 to the reservoir 16 by means of a fluid release valve assembly 20. The hydraulic jack is actuated by closing the valve assembly 20, pumping fluid through one-way check valves 22 and 24 in the piston and cylinder assembly 14. Pressure is released in the piston and cylinder assembly by opening the valve assembly 20 to allow fluid to flow back to the reservoir 16.

The Housing or Base Referring to FIGS. 10, 11 and 12, the housing or base 12 is cast from aluminum and includes a closed end bore or recess 28 and an open end bore 30 having a reduced diameter section 31. The closed end bore 28 defines the reservoir 16 and is connected to the open end bore 30 by means of a fluid passage network 15.

In this regard the fluid passage network 15 is connected to first and second closed end bores 32 and 34 which accommodate the pump assembly 18 and the release valve assembly 20. The fluid bore 32 includes a threaded reduced diameter section 36 at its inner end and a threaded section 38 at its outer end. The second bore 34 includes a reduced diameter'section 40 at its inner end having a threaded section 42 at the entry to the reduced diameter section 40 and a threaded section 44 at the inlet to the second bore 34.

Fluid Passage Network The fluid passage network 15 includes a threaded bore 54 connecting the reservoir 16 to the bore 32; a cross passage 56 connecting the reduced diameter section 36 to the reduced diameter section 42 of the closed end bore 34 and a return port 35 connecting the bore 34 to the reservoir 16. An enlarged section 58 is provided at the open end of passage 56 and includes threaded section 59. The passage 56 is closed at its outer end by means of a threaded plug 60. The enlarged section 58 is connected to the bore 30 by a port The flow of fluid from the reservoir 16 to the bore 32 is limited to one-way flow by means of a check valve assembly 22. The flow of fluid from the passage 32 to the passage 56 is controlled by means of a check valve assembly 24. The check valve assemblies 22 and 24 both include a steel valve seat 62 having a small diameter port 64 which terminates in an enlarged counterbore or recess 66. The ports 64 are closed by means of a steel ball 68 provided in counterbore 66. The ball 68 is biased by means of a spring 70 into engagement with the inner end of its small diameter port 64. The spring 70 is retained in the counterbore 66 by means of a spring retainer ring 71. The valve seats 62 are sealed by means of gaskets 63. I

The Pump Assembly 18 The pump assembly 18 includes a sleeve 72 having a threaded section 74 and is threadedly mounted in the threaded section 38 at the end of bore 32. The sleeve 72 is sealed within the bore 32 by means of. an O-ring seal 76 provided in a groove 78 in the outer surface of the sleeve 72. The sleeve 72 includes an axially extending bore 80 and is formed from a wear resistant material such as steel.

Fluid is pumped into and out of the bore 32 by means of a plunger 82 mounted for reciprocal movement in the bore 80. The plunger 82 is sealed therein by means of an O-ring seal 84 provided in an annular groove 86 in the sleeve 72.

The plunger 82 is reciprocated within the bore 80 by means of a beam 88 pivotally mounted on a beam pin 90 in the base 12. The beam 88 includes a clevis 96 which is connected to a clevis 92 on the end of the plunger 82 by means of a pin 95. The pin 95 extends through a groove 94 in the clevis 92 and openings 97 in the clevis 96. The beam 88 is rotated about the pin 90 by means of a handle 98 having one end seated within an opening 100 in the beam 88.

Relief Valve Assembly The flow of fluid from the bore 30 to the reservoir 16 is controlled by means of the release valve assembly positioned within the closed end bore 34. The assembly 20 includes a steel valve seat 26 which is threadedly positioned within the threaded section 42 in the small diameter bore 34. The valve seat 26 includes a small diameter opening 102. The flow of fluid through the opening 102 is controlled by means of a valve stem 104 which is positioned within a sleeve 106 provided in-the threaded section 44 in the bore 34. The valve stem 104 includes a valve member 108 at the inner end which is positioned to engage the end of the small diameter opening 102 in the valve seat 26. The valve stem 104 is sealed by means of an O-ring seal 110.

Plunger and Sleeve Assembly ln accordance with the invention, the plunger and sleeve assembly 14 includes a sleeve 112 and a plunger 114 having a piston head 116 positioned for reciprocal movement within the sleeve 112. The piston head 116 is sealed within the sleeve by means of an O-ring seal 118 provided in an annular groove 120 in the outer periphery of piston head 116. The lower end of the bore 30 is closed by means of a steel plug 122. The plunger 114 is prevented from moving out of the sleeve 112 by means of a stop ring 124 mounted at the open end of the bore 30. A saddle 126 can be provided at the outer end of the plunger 114, if required.

The sleeve 112 is formed of cast iron such as gray iron and is embedded and bonded in the aluminum casting forming the base 12 at the time that the base is cast. The lower end of the sleeve 112 is spaced from the reduced diameter section 31 leaving a gap 125. The sleeve 112 is retained or prevented from moving axially within the bore 30 by means of a shoulder or flange 128 provided at the lower end of the sleeve 112. Although a cast iron sleeve is shown and described, the sleeve could also be machined from an iron casting.

The sleeve 112 must be prevented from rotating in the casting 12 during machining or trimming of the bore in the sleeve 112. This is prevented by means of a number of ribs 132 provided on the outer surface of the sleeve. The rib 132 is embedded in the aluminum base during casting.

Fluid under pressure is prevented from flowing into the gap 125 by means of an O-ring seal 130. The seal 130 prevents the pressurized hydraulic fluid from reaching the bond between the sleeve and the casting.

Means are provided for pumping fluid from the reservoir 16 in any position of the jack 10. Such means is in the form of a rubber bladder positioned in the open end of reservoir 28. The bladder 140 is retained therein by means of a cover 142. Air is vented from the reservoir by means of a vent plug 144 threadedly mounted in threaded opening 146. A port 148 and cross bore 140 are provided in the plug to allow for the venting of air without removing the plug.

Resume In accordance with the invention each of the parts of the jack which is subject to wear or galling is made of a material which is resistant to such action. In this regard the plunger and sleeve assembly includes a sleeve 112 made of grey iron and a plunger 114 made of steel. The fluid control points in the fluid passage network are controlled by check valve assemblies 22 and 24 and relief valve assembly 20. Each of the check valve assemblies 22 and 24 includes a steel valve seat 62 and the release valve assembly 20 includes a steel valve seat 26. Although the use of steel for this purpose is generally well known, the incorporation of individual steel units in a lightweight housing has made it possible to provide a heavy duty jack which can be easily handled by the operator. The iron sleeve is provided with a shoulder and a number of ribs to securely lock the sleeve in the housing. The sleeve can then be machined or trimmed. The bond between the sleeve and housing has been protected by an O-ring seal.

l claim:

1. A hydraulic jack comprising a lightweight cast aluminum housing having a hydraulic liquid reservoir,

an iron sleeve cast into said housing to form an integral part thereof,

a steel plunger mounted for reciprocal motion in said sleeve,

means in said housing for pumping fluid under pressure from said reservoir into the interior of said sleeve and pressure release means for connecting the interior of said sleeve to said reservoir for relieving pressure in the interior of said sleeve,

said sleeve including a shoulder on the outer periphery of the inner end of said sleeve for preventing axial movement of said sleeve in said housing, sealing means located between the inner end of said sleeve and said housing whereby hydraulic fluid under pressure in said sleeve is prevented from flowing between said sleeve and housing and a stop ring threadably engaged in said housing and abutting against the outer end of said sleeve.

2. The jack according to claim 1 wherein said sleeve includes an axially extending rib on the outer surface to prevent rotation of said sleeve in said housing.

3. The hydraulic jack according to claim 1 wherein said pumping means includes a pair of one way check valves each having a steel valve seat.

4. The hydraulic jack according to claim 3 wherein said pressure release means includes a steel valve seat. l 

1. A hydraulic jack comprising a lightweight cast aluminum housing having a hydraulic liquid reservoir, an iron sleeve cast into said housing tO form an integral part thereof, a steel plunger mounted for reciprocal motion in said sleeve, means in said housing for pumping fluid under pressure from said reservoir into the interior of said sleeve and pressure release means for connecting the interior of said sleeve to said reservoir for relieving pressure in the interior of said sleeve, said sleeve including a shoulder on the outer periphery of the inner end of said sleeve for preventing axial movement of said sleeve in said housing, sealing means located between the inner end of said sleeve and said housing whereby hydraulic fluid under pressure in said sleeve is prevented from flowing between said sleeve and housing and a stop ring threadably engaged in said housing and abutting against the outer end of said sleeve.
 2. The jack according to claim 1 wherein said sleeve includes an axially extending rib on the outer surface to prevent rotation of said sleeve in said housing.
 3. The hydraulic jack according to claim 1 wherein said pumping means includes a pair of one way check valves each having a steel valve seat.
 4. The hydraulic jack according to claim 3 wherein said pressure release means includes a steel valve seat. 